Lock for ground engaging tool

1. A lock for a ground engaging tool, comprising:

a body portion having a first diameter;

a neck portion having a second diameter smaller than the first diameter, and extending from the body portion; and

a head portion extending from the neck portion, the head portion including:

a bottom surface facing the body portion;

a top surface facing away from the body portion;

first and second generally planar end surfaces extending from the bottom surface to the top surface; and

first and second cam surfaces extending from the bottom surface to the top surface, and connecting the first and second end surfaces, wherein the first and second cam surfaces each include a convex portion and a concave portion; and

wherein the convex portion of the first cam surface is adjacent the first generally planar end surface and has a smaller radius of curvature than the concave portion of the first cam surface adjacent the second generally planar end surface, and the convex portion of the second cam surface is adjacent the second generally planar end surface and has a smaller radius of curvature than the concave portion of the second cam surface adjacent the first generally planar end surface.

2. The lock of claim 1 , wherein the bottom and top surfaces of the head portion are generally planar.

3. The lock of claim 2 , wherein the bottom surface of the head portion is approximately parallel to the top surface of the head portion.

4. The lock of claim 3 , wherein the first and second generally planar end surfaces are approximately perpendicular to the bottom and top surfaces of the head portion.

5. The lock of claim 3 , wherein the first and second cam surfaces are approximately perpendicular to the bottom and top surfaces of the head portion.

6. The lock of claim 1 , wherein the neck portion extends from a generally cylindrical section of the body portion.

7. The lock of claim 6 , wherein the neck portion is generally cylindrical.

8. A lock for a ground engaging tool, comprising:

a body portion including:

a first section having a first diameter; and

a second section having a second diameter smaller than the first diameter;

a neck portion having a third diameter smaller than the second diameter, and extending from the second section; and a

head portion extending from the neck portion, the head portion including:

a bottom surface facing the body portion;

a top surface facing away from the body portion;

first and second generally planar end surfaces extending from the bottom surface to the top surface; and

first and second cam surfaces extending from the bottom surface to the top surface, and connecting the first and second end surfaces, wherein the first and second cam surfaces each include a convex portion and a concave portion; and

wherein the convex portion of the first cam surface is adjacent the first generally planar end surface and has a smaller radius of curvature than the concave portion of the first cam surface adjacent the second generally planar end surface, and the convex portion of the second cam surface is adjacent the second generally planar end surface and has a smaller radius of curvature than the concave portion of the second cam surface adjacent the first generally planar end surface.

9. The lock of claim 8 , wherein the bottom and top surfaces of the head portion are generally planar.

10. The lock of claim 9 , wherein the bottom surface of the head portion is approximately parallel to the top surface of the head portion.

11. The lock of claim 10 , wherein the first and second generally planar end surfaces are approximately perpendicular to the bottom and top surfaces of the head portion.

12. The lock of claim 10 , wherein the first and second cam surfaces are approximately perpendicular to the bottom and top surfaces of the head portion.

13. The lock of claim 8 , wherein the neck portion extends from a generally cylindrical section of the second section of the body portion.

14. The lock of claim 13 , wherein the neck portion is generally cylindrical.

15. A lock for a ground engaging tool, comprising:

a body portion including:

a first section having a first diameter; and

a second section having a second diameter smaller than the first diameter;

a neck portion having a third diameter smaller than the second diameter, and extending from the second section; and

a head portion extending from the neck portion, the head portion including:

a bottom surface facing the body portion;

a top surface facing away from the body portion;

first and second generally planar end surfaces extending from the bottom surface to the top surface; and

first and second cam surfaces extending from the bottom surface to the top surface, and connecting the first and second end surfaces, wherein the first and second cam surfaces each include a convex portion and a concave portion; and

wherein the convex portion of the first cam surface is adjacent the first generally planar end surface and has a smaller radius of curvature than the concave portion of the first cam surface adjacent the second generally planar end surface, and the convex portion of the second cam surface is adjacent the second generally planar end surface and has a smaller radius of curvature than the concave portion of the second cam surface adjacent the first generally planar end surface.

16. The lock of claim 15 , wherein the bottom and top surfaces of the head portion are generally planar.

17. The lock of claim 15 , wherein the bottom surface of the head portion is approximately parallel to the top surface of the head portion.

18. The lock of claim 15 , wherein the first and second generally planar end surfaces are approximately perpendicular to the bottom and top surfaces of the head portion.